Phenolic binders for mineral fiber thermal insulation

ABSTRACT

Aqueous phenolic resin binders emulsifiable in water containing resole modified with dicyandiamide or malamine, an alkoxymethylaminotriazine and a proteinaceous compound. The thermoset binders possess improved thermal stability and oxidation resistance. They may be used as binders of mineral fiber matrices to provide thermal insulation which is resistant to punking.

United States Patent 1191 Higginbottom 1451 Sept. 23, 1975 PI-IENOLICBINDERS FOR MINERAL FIBER THERMAL INSULATION [75] Inventor: Harold P.IIigginbottom,

Wilbraham, Mass.

[73] Assignee: Monsanto Company, St. Louis, Mo.

[22] Filed: Apr. 10, 1974 [21] Appl. No.: 459,524

5/1972 Ingram 260/7 '7/1974 Harding et al. 260/l 7.2

OTHER PUBLICATIONS Chem. Absts. Vol. 712(1969) 7l463e, Henkel und Cie,Molded Formaldehyde Resins containing Mineral Fibers.

Primary Exa'r'niner Melvin Goldstein Assistant Exarnir'zeF-EdwardWoodberry Attorney, Ager'z't, 0r FirmR. B. Blance; E. P. Grattan; J. C.Logomasini [57] ABSTRACT Aqueous phenolic resin binders emulsifiable inwater containing resole modified with dicyandiamide or malamine, analkoxy-methylaminotriazine and a proteinaceous compound. The thermosetbinders possess improved thermal stability and oxidation resistance.They may be used as binders of mineral fiber matrices to provide thermalinsulation which is resistant to punking.

20 Claims, 1 Drawing Figure THERMOGRAM 0F DECOMPOSITION OF CURED BINDERA. STANDARD COMMERCIAL PIIENOL/C BINDER 8. STANDARD ANT/PUNKING.COMMERCIAL PHE NOL/C BINDER C. ANT/PUNK/NG BINDER 0F PRiSE/VT INVE/VTIONEXO OAT

ENDO

US Patent Se t. 23,1975 3,907,724

THERMOGRAM 0F DECOMPOSITION OF CURED BINDER A STANDARD comma/ac m4Pym/our: SINOER E I l 5. STANDARD ANT/PUNK/NG. COMMRC/AL 5- pus NOL/'BINDER C. ANT/PUNK/NG BINDER OF PRESENT INVENTION ENDO PHENOLIC BINDERSFOR MINERAL FIBER THERMAL INSULATION BACKGROUND OF THE INVENTION 1.Field of the Invention The present invention relates tophenolformaldehyde liquid resin systems and to thermal insulation basedon mineral fibers bonded with these resin systems.

2. Description of the Prior Art The concept of mineral fibers bondedwith phenolformaldehyde resin was developed as a means of producingthermal insulation of low density. Such insulation is deficient in itsready susceptibility to flameless combustion or punking which isconsidered to be an autocatalytic oxidative degradation.

The art has employed various combinations of urea, melamine ordicyandiamide with phenol and formaldehyde to obtain so-calledantipunking resins. For optimum high temperature antipunking properties,significant levels of dicyandiamide or melamine or combinations of theseand a minimum combined formaldehyde are generally required. Severalsystems have been developed as means to achieve the desired properties:

A. Green phenolic resins obtained by limited reaction of phenol andformaldehyde, containing high concentrations of unreacted formaldehyde,which are coreacted with dicyandiamide or melamine to solubilize theantipunk additive. Such systems require that the dicyandiamide ormelamine be added to the resole while there is a high concentration ofunreacted formaldehyde and, hence, unreacted phenol so that there can besufficient reaction of dicyandiamide or melamine with formaldehyde tosolubilize them. Although the excess formaldehyde reacts preferentiallywith the melamine or dicyandiamide, the extent of reaction must be carefully regulated to minimize reaction of resole and dicyandiamide ormelamine since the reaction products reduce the water dilutability ofthe resin, particularly upon storage. Also, the high levels of combinedformaldehyde can lower the thermal stability of the system. Moreover,pollution problems arise from unreacted phenol and formaldehyde releasedduring the drying and curing steps;

B. Addition of either dicyandiamide or melamine as a hot aqueoussolution to the preformed phenolic resin at the time of application ofthe resin to the mineral fiber matrix. The addition of dicyandiamide ormelamine just prior to use is necessitated by the factthat thesecomponents will precipitate from solution on cooling, unless anundesirably large excess of formaldehyde is present. This approach,therefore, requires that the two components of the system be heated andcombined at the time of application; and

C. Antipunk or regular phenolic resins co-blended with water solublemelamine or other aminoplast resins just prior to use. Conventionaltechnology requires blending just before use since such combinationsshow rapid loss of water compatibility with time. This system alsorequires the handling and combination of twocomponents. Moreover, a highconcentration of melamine resin causes excessive dryness of the treatedmineral fiber matrix prior to cure of binder resin, and a decrease ofbonding strength and dustiness upon final cure.

Thus, there exists a need for a single aqueous phenolic resin systemwhich contains all the necessary antipunk ingredients to conferoxidation and thermal sta bility upon the thermal insulation preparedfrom the resin system, which is stable upon storage, and which can behandled like a conventional liquid phenolic resin upon application tothe mineral fiber matrix. For example, resin is generally applied froman aqueous system containing less than 8 percent solids. It is,therefore necessary for the resin to be blended with water without phaseseparation or formation of gummy deposits which might clog pumps, pipesand spray nozzles. Further, it is desirable that the resin shouldrelease a minimal quantity of pollutants to the atmosphere and should befree of dust formation during the drying and curing steps in thepreparation of the thermal insulation.

SUMMARY OF THE INVENTION The need is fulfilled by the present inventionwhich provides a stable, aqueous water-dilutable phenolic resin systemcontaining:

A. a modified resole comprising a phenolformaldehyde condensate and adicyandiamideformaldehyde condensate or a melamineforrnaldehydecondensate wherein the mole ratio of phenol to dicyandiamide or melamineis in the range of 1:020 to 1:12, wherein there are between 1.5 and 2.5moles of formaldehyde per mole of phenol and, additionally, between 0.9and 2.0 moles formaldehyde per mole of dicyandiamide or melamine,

B. an etherified methylolaminotriazine wherein the degree ofmethylolation is at least 1.5; the degree of etherification is at least0.5, and the etherification agent is an alcohol containing from 1 to 4carbon atoms, and

C. a proteinaceous compound soluble in aqueous media at a pH of 7 to 10;wherein the weight ratio of the modified resole and the etherifiedmethyloltriazine is in the range of l0:l to 1:2 and wherein the weightratio of proteinaceous compound to modified resole and etherifiedmethyloltriazine is in the range of 121000 and 1:20.

The modified resole is prepared by condensing dicy' andiamide ormelamine with formaldehyde at a temperature in the range of 20-70C. inthe presence of an alkaline aqueous solution of resole. Utilization ofan advanced resole contributes to low concentrations of free phenol andformaldehyde in the system. The modified resole can be further modifiedwith urea. The pH of the modified resole solution is adjusted to between7 and 8 and the etherified methylolaminotriazine and the proteinaceouscompound are added. The preferred methylolaminotriazines aremethylolmelamines, methylolguanamines, and methylolbenzoguanamines.While the etherified methylolaminotriazine improves and antipunkbehavior of the modified resole, it also acts with the proteinaceouscompound to improve the stability and the water dilutability of theaqueous system. V

Another aspect of the invention comprises the preparation of thermosetresins of improved thermal stability and flame retardance by drying theaqueous waterdilutable phenolic resin system and subjecting it to atemperature in the range of 200 to 500F. for a time sufficient tothermoset the resin.

In a further aspect of the invention, a matrix of mineral fiber istreated with the diluted aqueous phenolic resin system. The matrix isdried to provide a low density non-dusting moldable thermal insulationwhich may be molded at temperatures in the range of 200 to 500F. tothermoset the resin and provide shaped sections of insulation ofsuperior thermal'stability and oxi dation resistance.

PREFERRED EMBODIMENTS The phenolic resin systems of the presentinvention are prepared in several stages. First, a formalin solution isrefluxed with phenol in the presence of an alkaline catalyst to form aresole resin. Catalysts which may be used include alkali metalhydroxides, alkaline earth metal hydroxides, tertiary amines containingbetween I and 12 carbon atoms and quaternary ammonium hydroxidescontaining between I and 12 carbon atoms. The catalyst may be added insteps to moderate the exothermic reaction. The pH is preferably in therange 8 to 10. Reaction is carried out at a temperature in the range of50l00C. Excess formalin is used in the reaction which is carried out toyield a resole with a combined formaldehyde to phenol mole ratio in therange of L to 2.5. The reaction is continued until the free phenolcontent is less than 4 percent, preferably less amide or melamine in therange of 1:20 to 1:12. Reaction between the dicyandiamide or melamineand the free formaldehyde in the reaction mixture is carried out' untilthe formaldehyde concentration falls below 2 percent. The reactiontemperature is in the range of 2070C. The preferred range is 4060C. foran adequate rate of reaction with a minimum amount of undesirablereaction products. The formalin is sufficient to provide a mole ratio offormaldehyde combined with dicyandiamide or melamine in the range of0.9:l to 2:1 and a mole ratio of formaldehyde combined with phenol inthe range of 1.5:] to 2.5:]. All the formalin is conveniently added atthe first reaction step with phenol. Nitrogen bases such as ammonia andprimary and secondary amines containing between 1 and 12 carbon atomsmay be-added during the reaction stage of dicyandiamide or melamine withformaldehyde and act as pH regulators, resin modifiers and formaldehydescavengers. The amount of such base ranges between 0.1 and 10 parts byweight per 100 parts of phenol.

When the formaldehyde concentration has been reduced to less than 2percent, the pH of the reaction mixture is adjusted to between 7 and 8by addition of acid. The reaction is cooled and an etherifiedmethylolaminotriazine and an aqueous solution of proteinaceous compoundare added. An amber colored aqueous phenolic resin system is thusobtained. When alkaline earth metal hydroxides are used as thecatalyst,they are preferably precipitated from solution prior to addition of theproteinaceous compound to avoid insolubilization of the protein. Theprecipitation is conveniently carried out with carbon dioxide orsulfuric acid and the insoluble carbonate or sulfate is removed byfiltration or centrifugation.

The etherified methylolaminotriazines are obtained by reaction of anaminotriazine with formaldehyde to produce the methylol derivative whichis then etheri- 4 fied with an alcohol containing from 1 to 4 carbonatoms. The degree of methylolation is at least 1.5, that is, at least1.5 moles of formaldehyde are condensed with the aminotriazine and thedegree of etherification is at least 0.5, that is. at least 0.5 moles ofalcohol are reacted with one mole of methylolaminotrizine. The preferredaminotriazincs are melamine, guanamine, and b'enzoguanamine. The weightratio of resole modified with dicyandiamide or melamine to etherifiedmethyloltriazine is in the range of 10:1 to 1:2. At a ratio greater than10:], stability of the phenolic resin system is impaired. At a ratio ofless than 1:2, the phenolic resin system yields thermal insulation withlow bond strength manifested by a tendency of the resin to powder andform dust.

The aqueous solution of proteinaceous compound is prepared fromproteinaceous compounds which are well known to those skilled in theart. In general, the proteinaceous compounds are amphoteric but are usedin aqueous solution at a pH of from 7 to 10 for addition to the phenolicresin system. The solutions may be prepared in the presence of alkalimetal hydroxides and carbonates, ammonium hydroxide and water solublealiphatic amines. It is advantageous to add urea to the proteinaceoussolution as a viscosity control agent. The most commonly usedproteinaceous materials are casein and soya protein. Common molecularweights range from 100,000 to 400,000. The quantity of proteinaceouscompound necessary for stability of the aqueous water dilutable phenolicresin is determined by the degree of advancement of the resin. Ingeneral, a high-degree of advancement requires a high concentration ofproteinaceous compound. The preferred quantity of proteinaceous compoundis between 0.1 and 5 weight percent of the total resin solids. Below 0.]weight percent, the phenolic resin system loses its wateremulsifiability while above 5 weight percent proteinaceous compound,.thephenolic resin system exhibits impaired thermal stability.

In the application of the phenolic resin system to a matrix of mineralfiber in the preparation of thermal insulation, it is conventional toapply the resin as an aqueous solution containing less than 8 percentsolids. This solids concentration required that the prior art phenolicresin systems have a water tolerance of at least] 150 percent. Watertolerance is determined at 25C. by addition of water to the phenolicresin until a slight permanent haze forms. The tolerance is the weightof water present in the system at the haze point expressed as a percentby weight of the resin solids. Thus, where the haze pointoccurs when 100parts by weight of water impart haze to 100 parts by weight of' resoleresin solids, the tolerance is 1.00 percent. It has been a feature ofthe prior art that in order toobtain suchhigh levels of water tolerance,the phenolic resin systems must contain relatively green or unadvancedresin. -The resin systems of the present invention are distinct in thattheir water tolerance may be appreciably. less than 1150 percent becausethey form stable emulsions when they arediluted with water to solidscontents of 8 percent or less.

The phenolic resin system of the present invention can be blended withurea as an inexpensive extender without loss of stability although itsthermal characteristics are modified. Up to 0.7 mole urea per mole ofini- .tial phenol can be advantageously used for extending the phenolicresin system without excessive loss of thermal stability of the resin orphysical strength of the insulation prepared from the resin.

The following examples are set forth to illustrate more clearly theprinciples and practices of this invention to one skilled in the art.They are not intended to be restrictive but merely to be illustrative ofthe invention. Unless otherwise stated, all parts, percentages andratios are on a weight basis. Solids are determined by the Owens solidsmethod.

EXAMPLE 1 This example sets forth the preparation of an aqueous phenolicresin system of the present invention. I

Phenol (1.00 moles), 50 percent formalin (3.20 moles) and alkaline metalhydroxide catalyst (0.10 mole) are reacted at 70C. until theconcentration of formaldehyde drops to 9 weight percent. The reactionmixture is cooled below 60C. and dicyandiamide (0.55 moles) is added andreacted for twenty minutes. Urea (0.16 moles) and 28 percent ammonia(0.066 moles NH are added. The reaction mixture is held at about 50C.for minutes and is then neutralized to a pH of 7.8 to 8.0.Methoxymethylmelamine (65 percent aqueous solution, degree ofmethylolation 3.8, degree of etherification 2.0) and soya proteinsolution (20% in protein solids) are added in succession to the reactionmixture and blended with it. The solids ratio of resole tomethoxymethylmelamine to protein is 1000:338z12. A clear amber coloredfluid with a solids content of 60 percent, a free formaldehyde contentless than 1 per cent and a free phenol content of about 0.5 percent isobtained. The water tolerance of the fresh product is about 800 percent.A stable dispersion forms when water is added in excess of the watertolerance.

Premixing of the soya protein is accomplished as follows: Urea (30parts) is dissolved in water (48.5 parts) and soya protein (20 parts) isadded and slurried. After 30 minutes, ammonia solution (1.5 parts) isadded and allowed to mix for 30 minutes. The appropriate amount ofsolution is then added to the resin.

The resin which results from this example can be shipped and stored as asingle package. On storage for one to two months at a temperature in therange of 0 to 18C., there is no phase separation or precipitation ofinsoluble material. While the water tolerance decreases slightly, theresin retains its emulsifiability, yielding stable dispersions whenwater in excess of the water'tolerance is added.

In contrast, when the methoxymethylmelamine is omitted from the aqueousphenolic resin system, and

the resin is stored at a temperature in the range of l8C., crystallinedeposits appear overnight. The deposits tend to clog pumps and blockspray nozzles when the resin is sprayed on mineral fiber matrices.Within one week, the crystalline deposits increase to such an extentthat spray application becomes impossible.

EXAMPLE 2 EXAMPLE 3 The procedure of Example T is repeated with the samestarting materials except that the methoxymethylmelamine has a degree ofmethylolation of 2.5 and a degree of etherification of 1.0. The weightratio of modified resole to etherified methyloltriazine to protein is1000;340:12. The product has a solids content of 60 percent, a freeformaldehyde content of below 1 percent, and a free phenol content of0.48 percent.

EXAMPLE 4 This example-sets forth the preparation of an aqueous phenolicresin with a higher dicyandiamide content than Example ,1. The procedureof Example 1 is followed except that 0.0875 moles of alkali metalhydroxide catalyst is used, the dicyandiamide content is raised to 0.64moles and no ammonia addition is made. The solids ratio of resole tomethoxymethylmelamine to protein for this example is 1000:344z12. Theresin solu' tion has a solidscontent of 60 percent, a free formaldehydecontent of 0.75 percent, and a phenol content of 0.54 percent. The watertolerance is about 700 percent.

EXAMPLE 5 This example sets forth the preparation of an aqueous phenolicresin with a higher urea content than Example l. The procedure ofExample 1 is repeated except that the dicyandiamide is added when theconcentration of unreacted formaldehyde has fallen to 10 weight percent.Prilled urea (0.64 moles) is added but no ammonia addition is made. Thereaction is neutralized to a pH of 7.4. The methoxymethylmelamine andsoya protein solution are mixed in. The solids ratio of resole tomethoxymethylmelamine to. protein is 1000:542z1l. The resin has a freeformaldehyde content below 1 percent and a free phenol content of about0.5 percent. The water tolerance of the fresh product is about 900percent. A stable dispersion results when water in excess of the watertolerance is added. The

product resin has a solids content of about 63 percent.

EXAMPLE 6 This example sets forth the preparation of an aqueous phenolicresin with a high methoxymethylmelamine content. The procedure ofExample 1 is repeated except that the dicyandiamide is added when theconcentration of unreacted formaldehyde has fallen to 7 weight percent.No ammonia or urea are added. After pH adjustment of the resin, amethoxymethylmelamine (65 percent solids, degree of methylolation 2.5,degree of etherification 1.0) is added. The solids ratio of resole tomethoxymethylmelamine to proteinaceous compound is l000:l600:13.

A clear amber colored fluid with a solids content of 63 percent, a freeformaldehyde content of 0.5 percent and a free phenol content of about0.5 percent is ob tained. The water tolerance of the fresh product isabout 600 percent. A stable dispersion results when water is added inexcess of the water tolerance.

EXAMPLE 7 This example sets forth the preparation of an aqueous phenolicresin containing a low ratio of dicyandiamide to phenol. The procedureoutlined in Example 1 is repeated except that the dicyandiamide (0.28moles) is added when the concentration of unreacted formaldehyde hasfallen to 6 weight percent. Urea (0.48 moles) is added as indicated inExample 1. No

ammonia is added in this example. The product is neutralized to a pH of7.6-7.8. The solids ratio of resole to methoxymethylmelamine to proteinis 1000:l033:18. The water tolerance of the fresh product is about 600percent. A stable dispersion forms when water in excess of the watertolerance is added. The resin has a total solids content of about 62.5percent. The free formaldehyde content is below 1 percent and freephenol content is below 0.5 percent. No phase separation orprecipitation of insoluble material occurs when the resin is stored attemperatures in the range of l 8C. for l to 2 months.

EXAMPLE 8 methoxymethylbenzoguanamine of degree of methylolation of 3.8and degree of methylation of 'l .0. The phenolic resin product has awater tolerance of approximately 500 and exhibits good storagestability.

EXAMPLE l4 MIX STABILITY TEST To demonstrate the instability ofconventional antipunk phenolic resins blended with methoxymethylmelamineresins, the following experiment was devised. A conventional antipunkphenolic resin was blended with methoxymethylmelamine (65 percentsolids, de-

gree of methylolation 2.5, degree of etherification 1.0).

The ratio of phenolic resin solids to melamine resin solids was 3:1. Theindividual resins and the blend possessed infinite water toleranceinitially 10,000 percent). The resins and the blend were stored at 23C.and their water tolerance was determined over a period of time. The dataare presented in Table I.

TABLE I CHANGE IN WATER TOLERANCE OF RESINS WATER TOLERANCE, 71 (days at23C.)

RESIN (0) (4) (6) (8) (ll) l. Conventional antipunk phenolic 10,0006,360 5,702 2,412 1,316

liquid resin 2. Methoxymcthylmelamine resin l(),00() l(),000 1(),0()()l(),00() l0,000 (degree of methylolation 2.5, degree of etherification1.0) 3. 3:1 blend of resins I and 2 l0,()()0 1,678 1,119 746 466 4.Resin of Example 1 800 500 product is neutralized to a pH of 7.8 to 8.0.The solids ratio of modified resole to methoxymethylmelamine to proteinis 1000:342:12. The storage stable resin which results from this examplehas a solids content of approximately 60 percent, a free formaldehydecontent below 1 percent, a free phenol content of about 0.5 percent, anda water tolerance of 500 percent.

EXAMPLES 9-1 1 These examples set forth the preparation of aqueousphenolic resins containing higher alkyl ethers of methylolmelamine. Theprocedure of Example 1 is followed except that in Example 10ethoxymethylmelamine with degree of methylolation 5.8 and degree ofethylation 3.0 is used in place of methoxymethylmelamine; in Example 11,n-propoxymethylmelamine with degree of methylolation 5.8 and degree ofpropylation 2.0 is used, and in Example 12, n-butoxymethylmelamine withdegree of methylolation 5.8 degree of butylation 2.0 is used. Thephenolic resin products have water tolerances of approximately 200 andexhibit good storage stability.

EXAMPLE 12 The procedure of Example 1 is followed except that themethoxymethylmelamine is replaced with methoxymethylguanamine of degreeof methylolation 3.8 and degree of methylation 2.0. The phenolic resinproduct has a water tolerance of approximately 500 and exhibits goodstorage stability.

EXAMPLE 13 The procedure of Example 1 is followed except that themethoxymethylmelamine is replaced with EVALUATION OF THERMAL INSULATIONRESINS Thermal insulation is prepared by applying the phenolic resinsystem of the present invention to a matrix of mineral fiber. Thepreferred fiber is glass. For example, the phenolic resin system isdiluted with water to form a solution or dispersion containing between 2and 25 percent solids. The aqueous dispersion or solution is applied toa matrix of glass fibers in an amount sufficient to yield a matrixcontaining from about 2 to about 15 percent by weight of cured resin.The matrix is subjected to drying conditions by forcing a volume of airheated at F. through the matrix for a period of three minutes. The driedmatrix is placed in a mold and cured for 2 minutes at 400F. In anothermethod of preparing thermal insulation, the diluted solution ordispersion is sprayed onto glass fibers immediately after the fibershave been formed and while they are falling through the air onto aconveyor to form a mat. The mat is then advanced on the conveyorcompressed against another conveyor to the required density and isheated to a temperature in the range of 400500F.

The resins of the present invention have outstanding applicationcharacteristics and efficiency. The smaller quantity of volatile organicmaterial liberated during drying and curing of the impregnated matrixdecreases atmospheric pollution. The binder composition can beformulated with silanes and lubricants to gain property benefits wellknown to the art. The disclosed binders can be cured at temperaturesnormally used for thermal insulation manufacture (200 to 400F.) toproduce insulation with outstanding antipunking properties. However,optimum antipunking and thermal stability are obtained with insulationmanufactured from the disclosed binders by initial cure or post-cure attemperatures in the range of 400 to 500F.

HOT BALL PUNKING TEST Glass fiber thermal insulation test samples of oneinch thickness, approximately 2 pounds per cubic foot density andcontaining 12 percent by weight ofthe binder cured at a temperature of350F. are prepared. Six 4 inch X 4 inch X 1 inch test samples are cutfrom each insulation piece to be tested. The six pieces are stackedvertically to form a 4 inch X 4 inch X 6 inch composite. A one-half inchdiameter steel ball is heated to 1400F. in a muffle furnace. The test isconducted by separating the six-ply stack of test samples between thethird and fourth sample, placing the heated ball bearing at the exactcenter between the third and fourth sample, reforming the 4 inch X 4inch X 6 inch composite and immediately compressing the composite in thevertical direction from 6 inches to 3 inches in height.

The composite is held under compression for twenty minutes or untilpunking has subsided. The test pieces are then released fromcompression, opened between the third and fourth mat and the ballbearing removed. The darkened and decomposed area surrounding the ballon the 4 inch square face is then measured. The percent punking isdefined as:

Area decomposed Area of ball bearing punking Area of 4 inch face Area ofball bearing Area decomposed 0.]96 punking By this test, the followingcomparative results are obtained:

Ho'r PLATE TEST Glass fiber thermal insulation having 2 inch thickness,a density of 3.5 pounds per cubic feet and containing 9-l 1 percentcured binder content is prepared. Samples of the insulation are placedon the surface of a hot plate at 650F. for 2 hours and then they areremoved and examined. Samples made with the resin of Example I shownegligible surface degradation with no evidence of punking into the mat.Conventional general purpose antipunk binders give insulation sampleswhich show significantly more surface degradation and some punking intothe mat. Sample mats containing general purpose phenolic resins whichare not antipunking in nature show destructive decomposition of theresin and extensive punking within the body of the insulation mat.

PIPE INSULATION TEST A sample of the resin of Example I is diluted withwater to l8 percent solids. The aqueous resin is sprayed onto a matrixof glass fibers to give a mat containing about 8 percent by weight ofcured resin. The mat is subjected to drying conditions by forcing avolume of air heated at F. through it for a period of 3 minutes. Thedried mat is placed in a mold and cured for 2 minutes at 400F. to formsemi-cylindrical sections of 2 inch thickness 3 feet in length andhaving an interior diameter of 2 inches. The sections are applied to theexterior of a 2 inch diameter iron pipe and wound with asbestos-treatedcanvas and clamped. When the pipe is subjected to interior temperaturesup to 600F. the material does not exhibit punking or lose its insulationproperties.

DIFFERENTIAL SCANNING CALORIMETRY (DSC) EVALUATION OF BONDING RESINS Inorder to compare the exothermic decomposition of the example resins ofthis application and prior art resins, differential scanning calorimetry(DSC) data was obtained. A standard duPont 900 Differential ThermalAnalyzer equipped with a differential scanning calorimetry cell wasemployed. DSC allows a quantitative measure of the heat evolved whenresin decomposition occurs. Samples for comparison are prepared bycuring binders under conditions similar to those that would beencountered in a thermal insulation process but without the fibersubstrate being present. The cured binder is ground to a uniformparticle size to pass through a IO0140 mesh size. The exothermicdecomposition of 10.0 mg. samples is determined in a static atmosphereof air. The rate of heating is 30C. per minute over the temperaturerange of 25 to 500C.

The thermogram in FIG. 1 illustrates the comparative decompositionexotherms of commercial prior art resins of the antipunking andnon-antipunking type compared with products of this invention. Curve Ais the thermogram of a standard commercial type of phenolfonnaldehyderesin (non-antipunking). It shows a pronounced exotherm at 230C.followed by a broad massive exotherm from 250 to over 500C. The exothermat 230C. is regarded as the mechanism triggering punking. The broadexotherm caused by oxidative decomposition above 250C. provides thedestructive heat that builds within the insulation and causesuncontrolled punking. The thermogram of the decomposition of acommercial general purpose antipunk resin is shown in Curve B. Incomparison with Curve A, the triggering exothenn at 230C. and thegeneral exotherm in the 250-500C. region is substantially reduced. Thethermogram of the decomposition of a resin of the present invention, theresin of Example 3, is shown in Curve C. The triggering exotherm at230C. is eliminated and the general exothermic decomposition in the 250to 500C. region is reduced to a low level. The exothermillustrated byCurve C is controlled by varying the dicyandiamide or melamine content,the urea content and the etherified methylol aminotriazine content ofthe aqueous phenolic resin within the scope of the invention. A decreasein the exotherm is generally observed when the concentration of any ofthese components is increased.

From the foregoing, it is obvious that many variations are possible inthe practice of the invention, without departing from the spirit andscope thereof.

What is claimed is:

1. An aqueous phenolic resin system which cornprises: I

A. a modified resole comprising a phenolformaldehyde condensate and adicyandiamideformaldehyde or a melamineformaldehyde condensate whereinthe mole ratio of phenol todicyandiamide or melamine is in the range of1:02 to 1:12, wherein there are between 1.5 and 2.5 moles offormaldehyde per mole of phenol, and, additionally, between 0.9 and 2.0moles formaldehyde per mole of dicyandiamide or melamine,

B. an etherified methylolaminotriazine wherein the degree ofmethylolation is at least 1.5, the degree of etherification is at least0.5, and the etherification agent is an alcohol containing from 1 to 4carbon atoms, and

C. a proteinaceous compound soluble in aqueous media at a pH of 7 to 10;wherein the weight ratio of the modified resole to the etherifiedmethylolaminotriazine is in the range of 10:1 to 1:2 and wherein theweight ratio of the proteinaceous compound to the modified resole andthe etherified methylolaminotriazine is in the range of 1:1000 to 1:20.

2. The aqueous phenolic resin system of claim 1 wherein themethylolaminotriazine is selected from the group consisting ofmethylolmelamines, methylolguanamines and methylolbenzoguanamines.

3. The aqueous phenolic resin system of claim 1 wherein themethylolaminotriazine is a methylolmelamine and the alcohol ismethylalcohol.

4. The aqueous phenolic resin system of claim 1 wherein theproteinaceous compound is casein.

5. The aqueous phenolic resin of system claim 1 wherein theproteinaceous compound is soya protein.

6. The aqueous phenolic resin of system claim 1 which additionallycomprises up to 0.7 mole urea per mole of phenol.

7. An aqueous phenolic resin system which comprises:

A. a modified resole comprising a phenolformaldehyde condensate and adicyandiamideformaldehyde condensate wherein the mole ratio of phenol todicyandiamide is in the range of 1:02 to 1:12, wherein there are between1.5 and 2.5 moles of formaldehyde per mole of phenol, and, additionally,between 0.9 and 2.0 moles formaldehyde per mole of dicyandiamide,

B. a methoxymethylmelamine wherein the degree of methylolation is atleast 1.5 and the degree of methylation is at least 0.5, and

C. a proteinaceous compound selected from the group consisting of caseinand soya protein;

wherein the weight ratio of the modified resole to themethoxymethylmelamine is in the range of 10:1 to 1:2 and wherein theweight ratio of the proteinaceous compound to the modified resole andthe methoxymethylmelamine is in the range of 1:1000 to 1:20.

A. reacting formaldehyde and phenol'in a mole ratio of 1.5:1 to 2.5:] inan aqueous alkaline medium to form' a resole.

B. reacting formaldehyde with dicyandiamide or melamine in a mole ratioof 0.9:1 to 2.0:] in the presence of the aqueous alkaline resole at atemperature in the range of 2070C., to form a modified resole, v

C. adjusting the pH of the modified resole to between 7 and 9,

D. adding a methylolaminotriazine etherified with an alcohol containingfrom 1 to 4 carbon atoms, wherein the degree of methylolation is atleast 1.5 and the degree of etherification is at least 0.5, and

E. adding a proteinaceous compound soluble in aqueous media at a pH of 7to 10;

wherein the mole ratio of phenol to dicyandiamide or melamine is in therange of 1:02 to 1:12, wherein the weight ratio of the modified resoleto the etherified methylolaminotriazine is in the range of 10:1 to 1:2and wherein the weight ratio of the proteinaceous compound to themodified resole and the etherified methylolaminotriazine is in the rangeof 1:1000 to 1:20.

9. The process of claim 8 wherein the methylolaminotriazine is selectedfrom the group consisting of methylolmelamines, methylolguanamines andmethylolbenzoguanamines.

10. The process of claim 8 wherein the methylolaminotriazine is amethylolmelamine and the alcohol is methyl alcohol. I

l l. The process of claim 8 wherein the proteinaceous compound iscasein.

12. The process of claim 8 wherein the proteinaceous compound is soyaprotein.

13. A process for preparing an aqueous phenolic resin system whichcomprises:

A. reacting formaldehyde and phenol in a mole ratio of 1.5:1 to 25:1 inan aqueous alkaline medium to form a resole,

B. reacting formaldehyde and dicyandiamide or melamine in a mole ratioof 0.9:1 to 2.0:] in the presence of the aqueous alkaline resole at atemperature in the range of 4060C. to form a modified resole,

C. adjusting the pH of the modified resole to between 7 and 9,

D. adding a methoxymethylmelamine wherein the degree of methylolation isat least 1.5 and the degree of methylation isat least 0.5, and

I E. adding a proteinaceous" compound selected from the group consistingof casein and soya protein; wherein the mole ratio of phenol todicyandiamide is in the range of 1:02 to 1:12, wherein the weight ratioof the modified resole to the methoxymethylmelamine is in the range of10:1 to 1:2 and wherein the weight ratio of the proteinaceous compoundtothe modified resole and the methoxymethylmelamine is in the range of 8.A process for preparing an aqueous phenolic resin system whichcomprises:

14. A thermoset resin comprising the condensation product of an phenolicresin system which comprises:

A. a modified resole comprising a phenolformaldehyde condensate and adicyandiamideformaldehyde or a melamineformaldehyde condensate whereinthe mole ratio of phenol to dicyandiamide or melamine is in the range of1:02 to 1:12, wherein there are between 1.5 and 2.5 moles offormaldehyde per mole of phenol, and, additionally, between 0.9 and 2.0moles formaldehyde per mole of dicyandiamide or melamine,

B. an etherified methylolaminotriazine wherein the degree ofmethylolation is at least 1.5, the degree of etherification is at least0.5, and the etherification agent is an alcohol containing from 1 to 4carbon atoms, and

C. a proteinaceous compound soluble in aqueous media at a pH of 7 to 10;

wherein the weight ratio of the modified resole to the etherifiedmethylolaminotriazine is in the range of 10:1 to 1:2 and wherein theweight ratio of the proteinaceous compound to the modified resole andthe etherified methylolaminotriazine is in the range of 1:1000 to 1:20.

15. The thermoset resin of claim 14 wherein themethylolaminotriazine isselected from the group consisting of methylolmelamines,methylolguanamines and methylolbenzoguanamines.

16. The thermoset resin of claim 14 wherein the methylolaminotriazine isa methylolmelamine and the alcohol is methyl alcohol.

17. The thermoset resin of claim 14 wherein the proteinaceous compoundis casein.

18. The thermoset resin of claim 14 wherein the proteinaceous compoundis soya protein.

19. The thermoset resin of claim 14 wherein the admixture comprisesadditionally up to 0.7 mole urea per mole of phenol.

20. A thermoset resin comprising the condensation product of an phenolicresin system which comprises:

A. a modified resole comprising a phenolformaldehyde condensate and adicyandiamideformaldehyde condensate wherein the mole ratio of phenol todicyandiamide is in the range of 1:02 to 1:1.2, wherein there arebetween 1.5 and 2.5 moles of formaldehyde per mole of phenol. and.additionally, between 0.9 and 2.0 moles formaldehyde per mole ofdicyandiamide.

B. a methoxymethylmelamine wherein the degree of methylolation is atleast 1.5 and the degree of methylation is 0.5,

C. a proteinaceous compound selected from the group consisting of caseinand soya protein;

wherein the weight ratio of the modified resole to themethoxymethylmelamine is in the range of 10:1 to 1:2 and wherein theweight ratio of the proteinaceous compound to the modified resole andthe methoxymcthylmelamine is in the range of 1:1000 to 1:20.

1. AN AQUEOUS PHEOLIC RESIN SYSTEM WHICH COMPRISES: A. A MODIFIED RESOLECOMPRISING A PHENOL-FORMALDEHYDE CONDENSATE AND ADICYANDIAMIDE-FORMALDEHYDE OR A MELAMINEFORMALDEHYDE CONDENSATE WHEREINTHE MOLE RATIO OF PHENOL TO DICYANDIAMIDE OR MELAMINE IS IN THE RANGE OF1:0.2 TO 1:1.2, WHEREIN THERE ARE BETWEEN 1.5 AND 2.5 MOLES OFFORMALDEHYDE PER MOLE OF PHENOL, AND, ADDITIONALLY, BETWEEN 0.9 AND 2.0MOLES FORMALDEHYDE PER MOLE OF DICYANDIAMIDE OR MELAMINE, B. ANETHERIFIED METHYLOLAMINOTRIAZINE WHEREIN THE DEGREE OF METHYLOLATION ISAT LEAST 1.5, THE DEGREE OF ETHERIFICATION IS AT LEAST 0.5, AND THEETHERIFICATION AGENT IS AN ALCOHOL CONTAINING FROM 1 TO 4 CARBON ATOMS,AND C. A PROTEINACEOUS COMPOUND SOLUBLE IN AQUEOUS MEDIA AT A PH OF 7 TO10, WHEREIN THE WEIGHT RATIO OF THE MODIFIED RESOLE TO THE ETHERIFIEDMETHYLOLAMINOTRIAZINE IS IN THE RANGE OF 10:1 TO 1:2 AND WHEREIN THEWEIGHT RATIO OF THE PROTEINACEOUS COMPOUND TO THE MODIFIED RESOLE ANDTHE ETHERIFIED METHYLOLAMINOTRAZINE IS IN THE RANGE OF 1:1000 TO 1:20.2. The aqueous phenolic resin system of claim 1 wherein themethylolaminotriazine is selected from the group consisting ofmethylolmelamines, methylolguanamines and methylolbenzoguanamines. 3.The aqueous phenolic resin system of claim 1 wherein themethylolaminotriazine is a methylolmelamine and the alcohol ismethylalcohol.
 4. The aqueous phenolic resin system of claim 1 whereinthe proteinaceous compound is casein.
 5. The aqueous phenolic resin ofsystem claim 1 wherein the proteinaceous compound is soya protein. 6.The aqueous phenolic resin of system claim 1 which additionallycomprises up to 0.7 mole urea per mole of phenol.
 7. An aqueous phenolicresin system which comprises: A. a modified resole comprising aphenol-formaldehyde condensate and a dicyandiamide-formaldehydecondensate wherein the mole ratio of phenol to dicyandiamide is in therange of 1:0.2 to 1: 1.2, wherein there are between 1.5 and 2.5 moles offormaldehyde per mole of phenol, and, additionally, between 0.9 and 2.0moles formaldehyde per mole of dicyandiamide, B. a methoxymethylmelaminewherein the degree of methylolation is at least 1.5 and the degree ofmethylation is at least 0.5, and C. a proteinaceous compound selectedfrom the group consisting of casein and soya protein; wherein the weightratio of the modified resole to the methoxymethylmelamine is in therange of 10:1 to 1:2 and wherein the weight ratio of the proteinaceouscompound to the modified resole and the methoxymethylmelamine is in therange of 1:1000 to 1:20.
 8. A process for preparing an aqueous phenolicresin system which comprises: A. reacting formaldehyde and phenol in amole ratio of 1.5:1 to 2.5:1 in an aqueous alkaline medium to form aresole, B. reacting formaldehyde with dicyandiamide or melamine in amole ratio of 0.9:1 to 2.0:1 in the presence of the aqueous alkalineresole at a temperature in the range of 20*-70*C., to form a modifiedresole, C. adjusting the pH of the modified resole to between 7 and 9,D. adding a methylolaminotriazine etherified with an alcohol containingfrom 1 to 4 carbon atoms, wherein the degree of methylolation is atleast 1.5 and the degree of etherification is at least 0.5, and E.adding a proteinaceous compound soluble in aqueous media at a pH of 7 to10; wherein the mole ratio of phenol to dicyandiamide or melamine is inthe range of 1:0.2 to 1:1.2, wherein the weight ratio of the modifiedresole to the etherified methylolaminotriazine is in the range of 10:1to 1:2 and wherein the weight ratio of the proteinaceous compound to themodified resole and the etherified methylolaminotriazine is in the rangeof 1:1000 to 1:20.
 9. The process of claim 8 wherein themethylolaminotriazine is selected from the group consisting ofmethylolmelamines, methylolguanamines and methylolbenzoguanamines. 10.The process of claim 8 wherein the methylolaminotriazine is amethylolmelamine and the alcohol is methyl alcohol.
 11. The process ofclaim 8 wherein the proteinaceous compound is casein.
 12. The process ofclaim 8 wherein the proteinaceous compound is soya protein.
 13. Aprocess for preparing an aqueous phenolic resin system which comprises:A. reacting formaldehyde and phenol in a mole ratio of 1.5:1 to 2.5:1 inan aqueous alkaline medium to form a resole, B. reacting formaldehydeand dicyandiamide or melamine in a mole ratio of 0.9:1 to 2.0:1 in thepresence of the aqueous alkaline resole at a temperature in the range of40*-60*C. to form a modIfied resole, C. adjusting the pH of the modifiedresole to between 7 and 9, D. adding a methoxymethylmelamine wherein thedegree of methylolation is at least 1.5 and the degree of methylation isat least 0.5, and E. adding a proteinaceous compound selected from thegroup consisting of casein and soya protein; wherein the mole ratio ofphenol to dicyandiamide is in the range of 1:0.2 to 1:1.2, wherein theweight ratio of the modified resole to the methoxymethylmelamine is inthe range of 10:1 to 1: 2 and wherein the weight ratio of theproteinaceous compound to the modified resole and themethoxymethylmelamine is in the range of 1:1000 to 1:20.
 14. A thermosetresin comprising the condensation product of an phenolic resin systemwhich comprises: A. a modified resole comprising a phenol-formaldehydecondensate and a dicyandiamide-formaldehyde or a melamineformaldehydecondensate wherein the mole ratio of phenol to dicyandiamide or melamineis in the range of 1:0.2 to 1:1.2, wherein there are between 1.5 and 2.5moles of formaldehyde per mole of phenol, and, additionally, between 0.9and 2.0 moles formaldehyde per mole of dicyandiamide or melamine, B. anetherified methylolaminotriazine wherein the degree of methylolation isat least 1.5, the degree of etherification is at least 0.5, and theetherification agent is an alcohol containing from 1 to 4 carbon atoms,and C. a proteinaceous compound soluble in aqueous media at a pH of 7 to10; wherein the weight ratio of the modified resole to the etherifiedmethylolaminotriazine is in the range of 10:1 to 1:2 and wherein theweight ratio of the proteinaceous compound to the modified resole andthe etherified methylolaminotriazine is in the range of 1:1000 to 1:20.15. The thermoset resin of claim 14 wherein the methylolaminotriazine isselected from the group consisting of methylolmelamines,methylolguanamines and methylolbenzoguanamines.
 16. The thermoset resinof claim 14 wherein the methylolaminotriazine is a methylolmelamine andthe alcohol is methyl alcohol.
 17. The thermoset resin of claim 14wherein the proteinaceous compound is casein.
 18. The thermoset resin ofclaim 14 wherein the proteinaceous compound is soya protein.
 19. Thethermoset resin of claim 14 wherein the admixture comprises additionallyup to 0.7 mole urea per mole of phenol.
 20. A thermoset resin comprisingthe condensation product of an phenolic resin system which comprises: A.a modified resole comprising a phenol-formaldehyde condensate and adicyandiamide-formaldehyde condensate wherein the mole ratio of phenolto dicyandiamide is in the range of 1:0.2 to 1: 1.2, wherein there arebetween 1.5 and 2.5 moles of formaldehyde per mole of phenol, and,additionally, between 0.9 and 2.0 moles formaldehyde per mole ofdicyandiamide, B. a methoxymethylmelamine wherein the degree ofmethylolation is at least 1.5 and the degree of methylation is 0.5, C. aproteinaceous compound selected from the group consisting of casein andsoya protein; wherein the weight ratio of the modified resole to themethoxymethylmelamine is in the range of 10:1 to 1:2 and wherein theweight ratio of the proteinaceous compound to the modified resole andthe methoxymethylmelamine is in the range of 1:1000 to 1:20.